Its very interesting problem. It does sound like a possible clash with scenery and this particular aircraft, but again, if other planes are landing fine for you..... My suggestion is the same as the aforementioned, you should be landing with less than fifty percent fuel on board. That definetly makes landings more apt to succeed. I've had a somewhat similar problem …. the default airbus in FSX , ALWAYS goes into a dive after approximately 20 seconds after takeoff. I deleted FSX and reloaded it but nothing worked. Finally gave up and don't fly the aircraft.